During a long drive I had one of my, 'Ah I should try this on the Pro 2!' thoughts.
Am I wrong in thinking that Ext Input Level isn't a mod destination? I know it's not in the original list, and it's unlikely I've missed it in an update.. but you know, hopeful.
My plan was to combine a synth sequence with a live trumpet that was being gated with changing levels by the sequencer.